Document structures for searching within and across messages

A method, comprising:

• storing, by one or more computer systems, a conversation comprising a series of messages exchanged among a number of participants in a set of documents, wherein the set of documents comprises:
• a first document comprising metadata for the conversation;
• a second document comprising message content for the series of messages, wherein each message in the series of messages is stored in the second document with a fixed position gap between individual messages, the fixed position gap having a length that is twice the length of a predetermined maximum message length;
• and
• one or more additional documents, wherein each of the one or more additional documents stores message metadata for an individual message in the series of messages;
• processing, by the one or more computer systems, a first search for a first term across the series of messages in the conversation using an index of the set of documents;
• and
• process, using the index, a second search for a second term within individual messages in the series of messages as a span query with a distance that is greater than or equal to the predetermined maximum message length for each message in the series of messages and less than or equal to half the length of the fixed position gap.

A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method, the method comprising:

• storing a conversation comprising a series of messages exchanged among a number of participants in a set of documents, wherein the set of documents comprises:
• a first document comprising metadata for the conversation;
• a second document comprising message content for the series of messages, wherein each message in the series of messages is stored in the second document with a fixed position gap between individual messages, the fixed position gap having a length that is twice the length of a predetermined maximum message length;
• one or more additional documents, wherein each of the one or more additional documents stores message metadata for an individual message in the series of messages;
• processing a first search across the series of messages in the conversation using an index of the set of documents;
• and
• processing, using the index, a second search within individual messages in the series of messages as a span query with a distance that is greater than or equal to the predetermined maximum message length for each message in the series of messages and less than or equal to half the length of the fixed position gap.